With increase in recognition of recycling usage of biological resources, a lot of kinds of organic wastes have recently been composted and reduced to the earth as resource. Food wastes, such as livestock excreta (wastes) and food scraps (hereinafter these are collectively referred to as “livestock excreta (wastes) and the like”), which are the livestock excreta (wastes) that is most expected to be composted and/or resourced, often has high moisture, or so-called in a quagmire state, at the time of generation. For such livestock excreta (wastes) and the like, there are difficulties, such as that oxygen is hardly introduced inside the livestock excreta (wastes) and the like because of the quagmire state, that the biochemical reaction by the ordinary microbial degradation is difficult to occur, and that the livestock excreta (wastes) and the like are difficult to be composted. As a result, conventionally, a method that reduces a water content ratio in order to take in the oxygen inside the livestock excreta (wastes) has been adapted.
As one of the means to reduce the water content ratio, there is a method to provide heat energy, aeration and the like to the organic waste. However, such a method is not realistic due to an issue of the cost. In addition, as another means, in the case of the livestock excreta (wastes), for example, there is a method to mix agricultural by-products, such as sawdust, rice straws, rice husk and the like, with the organic waste. This method reduces the moisture contained in the organic waste and, as a result, to ease the airflow to promote the biochemical reaction by microbial degradation. However, the agricultural by-products may be difficult to procure in some regions, or the cost for procuring the agricultural by-products may increase. Moreover, even when the agricultural by-products can be obtained, the cost may further increase due to the additional processing of the agricultural by-products. Furthermore, in this method, there is a difficulty that the mixture of such agricultural by-products causes an increase in costs as the total amount of treatment increases.
Below Patent Document 1 proposes a method for the wastes recycling by heating and stirring the livestock excreta (wastes) and the like in a container to compost the waste. However, in this method also, the water content ratio needs to be reduced by providing the heat energy and the like, similar to those discussed above, to the organic waste having a high water content ratio, and thus, there is still an issue in terms of the cost.